Light alkanes are becoming increasingly abundant and lower in value as volatility restrictions limit their use in gasoline. At the same time aromatic hydrocarbons, which are the traditional sources of octane, are under fire from the Clean Air Act. A highly-branched paraffinic alkylate would be a very desirable high-octane alternative to aromatics. Such an alkylate is conventionally made from light olefins and isoparaffins, but the light olefins are very expensive relative to light alkanes. Thus, a process which could couple the light alkanes to give a highly-branched paraffinic product would be an economically attractive solution to both the problems of light alkane oversupply and high octane needs. No such process currently exists. Our invention provides one.